Improvement in apparatus for concentrating and evaporating sulphuric acid



UNITED S'IA'IEs PATENT OFFICE.

MARIE J. F. R. FAURE AND JACQUES I.. KEssLER, oF CLERMONT-FERRAND, "FRANCE IMPROVEMENT lN'APPAR-ATUS FOR'CONCENTRATING AND EVAPORATING SULPHURIC ACID.

Specification forming part of Letters Patent No.` 158,924, dated January 19, 1875; application filed June 2,9, 1874.

LER, both of Clermont-Ferrand, France, have invented certain Improvements in Apparatus for Goncentrating and Evaporating Sulphuric Acid, of which the following is aspecilication:

The object of our invention is an apparatus for concentrating acids, in Which, by maintaining but a small body of liquor at one time in the evaporating-pan, the necessity of employing a high temperature and a pan of such thickness as Will resist this temperature are avoided. rlhe apparatus is made in sections connected by a joint, in which the formation of vapor and consequent leakage are prevented by means of a surrounding Water-circulating chamber.

Figure l is a sectional elevation of the apparatus, and Figs. 2 and 3 enlarged sectional views illustrative of the join ts. A is a shallow circular basin, of platinum, provided with an inlet-tube, b, and outlet-tube a of the same material, and arranged directly over afurnace, B, the said basin being secured at its upper edge to a lead ring, G, forming a gutter or receptacle for the Weak acid obtained by the condensation of the vapors in the upper portion or bell F of the apparatus. The basin A is supported by a cast-iron ring, E, and the latter in turn supports a lead-covered iron ring, g', upon which the gutter G rests. The basin is luted to the gutter G by mastic or clay d, as shown in the enlarged views, Figs. 2 and 3, and the upper edge of the said basin may be bent over soas to project into the Weak acid contained in the gutter Gr, thus forming a hydraulic joint with the latter, as shown` by dotted lines in Fig. 3. .The character of the joint is of much importance, as heretofore, owing to the heating of the liquor in the joint, vapors have been formed, Which-permeate the joint, driving the liquor before them. Two forms of joint, Which have been found in practice to correct these evils, are shown in Figs. 2 and 3.

In Fig. 2 a leaden belt, c, surrounds and is luted to the upper edge of the basin A by mastic of manganese or clay d. Within this belt is a band, c1, of iron, steel, or copper, the ends of which are Wired together, as shown at o2. The belt c is Vsurrounded by bands e and f, soldered together and to the gutter Gr at f1. The joint, Fig. 3, is of a more simple character` the -upper portion of the platinum basin being luted directly to the gutter G by clay or mastic d., and the said basin being corrugated or fluted, asshoWn at so as to afford a good hold for the said luting. The gutter (in each form of joint) has double Walls, forming a space, y, in which cold water circulates, thereby maintaining the liquor cool, preventing the generation of vapor, and the consequent leakage. rlhe upper portion o r bell F of the apparatus does not rest directly upon the platinum basin, or upon the gutter G, but is supported by three standards, lo, to Which it is secured by rings h and arms t', the said standards resting upon the top of the furnace B, and being provided with rings kl at the top, which permit the Whole bell to be readily lifted from the platinum vesselv and gutter when access has to be had to these parts. The gutter G is supported at its upper edge by an iron ring, to Which is secured an annular vessel, g, ot' lead, this vessel receiving the lower edge of the bell F ofthe apparatus, and being filled with Water so as to form a perfectly-tight hydraulic joint. At the top of the bell F there is a hydraulic joint, o, With the pipe p, through which uncondensed vapors are carried off to be treated elsewhere, and surrounding the said joint there is a pan, l, from which Water is caused to overflow continuously, this Water flowing over the top of the bell and lling a series of Water-receptacles, m, m1, and m2, Which surround the bell, and which successively overiiow, one feeding the other. The Water is conducted olf from the lowermost receptacle m2 through a pipe, fn.

'In using the apparatus the sulphuric acid to be treated is introduced into the pan A through the pipe b, and after having been sufficiently concentrated by the heat of the furnace B is conducted oli' through the pipe a. The vapors which escape from the acid thus treated rise into the bell F, by contact With the cooled Walls of which they are rapidly con s y 15s, 924

densed, and fall in the form of very weak acid into the gutter G, whence they are discharged through a pipe, q, and tested from time to time.

By means of a platinum cock in the pipe t or a lead siphon, the current of sulphuric acid may be easily regulated in proportion to the intensity of the heat applied, so that the acid leaving the apparatus may have the required density.

The pipe a is arranged at such a distance from the bottom of the pan that but a small body of liquor can remain in the pan. A re of less intensity is therefore required to heat the liquor and maintain it at the proper temperature than when a large volume is treated at one time, While a much lighter and less expensive pan is required that must be used to resist the effects of aconstant high temperature, and to retain a large quantity of liquor. It will be apparent, however, that the productive capacity of the apparatus is not re-v duced by the diminished size of the pan, as the liquor is evaporated in one as quickly as in the other, and in this case is supplied as fast as it is condensed and removed.

We may observe that several of our improved apparatus may be coupled, the exittube a of one being continued into the inlettube b of the next. The capacity of the apparatus can also be increased Without complicat- 111g 1t, by using several separate inlet and outlet pipes, each provided with regulating dev1ces.

When the sulphuric acid is concentrated above 60 3 Baume the cooling of the bell F with Water may be dispensed with, for the vaporswill then contain only a trace of acid, which could not be economically recovered.

We claim as our inventionl. The combination, in an evaporating apparatus, of the bell F, pan A, inlet l), and outlet a, communicating with the pan a short distance above the bottom, as and for the purpose set forth.

2. The combination of the pan A, the gutter G, luted to the pan, and the bell F, resting in a groove at the upper edge of the gutter, as set forth. y

3. A cold-Water channel, i combined with the joint between the bell F and pan A, substantially as and for the purpose set forth.

4. rEhe combination ofthe basin A, annular gutter G, standards k, and bell F, supported by the standards above the basin, as set forth.

1n testimony whereof We have signed our names to this specification in the presence of two subscribing Witnesses.

MARIE JOSEPH FRANCOIS REGIS FAURE. JACQUES LOUIS KESSLER.

Witnesses EMILE RICHARD, CHARLES F. THIRION. 

